Bug 1539321 - Remove unused aboutdebugging debugAddon helper r=remote-debugging-reviewers,daisuke

This helper was only used by the old aboutdebugging and can be removed

Differential Revision: https://phabricator.services.mozilla.com/D38842

--HG--
extra : moz-landing-system : lando

devtools/client/aboutdebugging-new/src/modules/extensions-helper.js

@@ -18,38 +18,8 @@ loader.lazyRequireGetter(
   true
 );
 
-const { Toolbox } = require("devtools/client/framework/toolbox");
-const { gDevTools } = require("devtools/client/framework/devtools");
-
 const { PREFERENCES } = require("../constants");
 
-let addonToolbox = null;
-
-/**
- * Start debugging an addon.
- *
- * @param {String} id
- *        The addon id to debug.
- * @param {DebuggerClient} client
- *        Required for debugging.
- */
-exports.debugAddon = async function(id, client) {
-  const addonFront = await client.mainRoot.getAddon({ id });
-
-  const target = await addonFront.connect();
-
-  // Close previous addon debugging toolbox.
-  if (addonToolbox) {
-    addonToolbox.destroy();
-  }
-
-  const hostType = Toolbox.HostType.WINDOW;
-  addonToolbox = await gDevTools.showToolbox(target, null, hostType);
-  addonToolbox.once("destroy", () => {
-    addonToolbox = null;
-  });
-};
-
 /**
  * Uninstall the addon with the provided id.
  * Resolves when the addon shutdown has completed.